An integrated optical device fabricated in the back end of line process located within the vertical span of the metal stack and having one or more advantages over a corresponding integrated optical device fabricated in the silicon on insulator layer.

A photonic integrated circuit (PIC) having a substrate in which vertically coupled photodetectors and in-line optical modulators are integrated to enable vertical coupling of light using a fiber assembly block (FAB), with the planar end surface thereof being attached to a substantially planar main surface of the substrate. In an example embodiment, the photodetectors are buried in deep vias formed in the substrate, and the in-line optical modulators are waveguide-connected to the corresponding vertical-coupling optical gratings. The photodetectors and optical gratings may be arranged in a linear array along the main surface of the substrate to enable uncomplicated optical alignment of end segments of the optical fibers in the FAB with the corresponding photodetectors and optical gratings for vertical coupling of light therebetween. In some embodiments, the FAB may have more than one hundred optical fibers. In some embodiments, the PIC can be implemented using the silicon photonics material platform.

An example device comprises: a substrate comprising a waveguide material having a waveguide refractive index (RI.sub.WG); a first layer of oxide on the substrate having an RI.sub.1 lower than the RI.sub.WG; a waveguide on the first oxide layer, the waveguide comprising the waveguide material having the RI.sub.WG; a second oxide layer on the waveguide and the first oxide layer, the second oxide layer having a second RI.sub.2 higher than the RI.sub.1 and less than the RI.sub.WG, the first oxide layer, the waveguide and the second oxide layer forming an end face for light coupling, and the waveguide extending inwards from the end face and increasing in effective RI from the end face; and an index matching material on the second oxide layer that encapsulates at least the second oxide layer and the end face, a respective RI of the index matching material being about index matched to the RI.sub.1.

The invention described herein pertains to the structure and formation of dual core waveguide structures and to the formation of optical devices including spot size converters from these dual core waveguide structure for the receiving and routing of optical signals on substrates, interposers, and sub-mount assemblies.

An electro-optical system, and method for making the electro-optical system. The electro-optical system includes a Photonic Integrated Circuit (PIC) having a laser source located on the PIC, a fiberless optical coupler located on the PIC. The fiberless optical coupler is configured to be coupled to a fiber array. The electro-optical system also includes an optical element, and a mechanical aligner. The optical element is aligned with the fiber array, via the mechanical aligner, for a light from the laser source to transmit in between the fiber array and the PIC through the optical element, when the fiberless optical coupler is coupled to the fiber array.

Structures for an edge coupler of a photonics chip and methods of forming an edge coupler for a photonics chip. The structure includes a waveguide core on a dielectric layer, as well as an interconnect structure including a interlayer dielectric layer positioned over the dielectric layer and an opening penetrating through the interlayer dielectric layer to the waveguide core. A region of the interlayer dielectric layer is positioned to overlap with a portion of the waveguide core. The region of the interlayer dielectric layer has a surface that is rounded with a curvature.

Optical guiding elements are 3D printed on the ends of optical fibers. A multifiber connector includes fibers having 3D printed elements that are flush with the end face of the connector. The printed 3D element may be down-tapered for coupling between a single mode optical fiber and an optical chip waveguide. The cross-sectional shape of the 3D printed optical element may change along its length so as to more closely match to the mode field of a non-circular waveguide on the optical chip. The optical element may be printed with a gradient index. The optical element may be provided with an output face distal from the optical fiber that is not flat and which changes the divergence of the light passing therethrough.

An optical assembly for realizing horizontal and vertical spot-size conversion to couple light from a thin waveguide to a thick waveguide is disclosed. The assembly comprises at least one first thin waveguide with a first section having a first optical mode field and a horizontal spot-size expansion section providing spot-size conversion for a first horizontal dimension of said first optical mode field of a light beam propagating in said first waveguide, and at least one second thick waveguide with a second section having a second optical mode field and a horizontal spot-size reduction section providing spot-size conversion for a second horizontal dimension of said second optical mode field of a light beam propagating in said second waveguide. The expanded end of said first waveguide is aligned and rotated to interface with the reduced end of said second waveguide, so that the mode fields in said first and second waveguides are rotated 90 degrees with respect to each other, whereby the spot size of a light beam so coupled between the first and second waveguides is expanded or shrunk in both transverse dimensions, depending on the direction of the light beam.

A wideband photonic bump (WBB), including: a positive taper of a polymer waveguide configured to further expand a light beam from an inverse taper to match a fiber optical mode of an optical fiber; a curved mirror formed on a surface of the WBB configured to reflect a light beam from the optical fiber; and a tilted flat mirror configured to direct the reflected light beam to an external optical fiber, wherein the WBB is coupled on the surface of a photonic integrated circuit (PIC).

An optical connection element includes a first waveguide core and a second waveguide core above a substrate or a cladding and in which signal light and resin curing light propagate through the first waveguide core and the second waveguide core, the optical connection element including: an inter-core light coupling section in which a part of the first waveguide core and a part of the second waveguide core overlap in a perpendicular direction; and a resin curing light coupling section that couples resin curing light to the second waveguide core.